Using a scavenger agent (e.g., remove, add, deplete, or redistribute impurity or dopant)

4

20110114012

METHODS FOR PURIFYING METALLURGICAL SILICON - A method for purifying silicon bearing materials for photovoltaic applications includes providing metallurgical silicon into a crucible apparatus. The metallurgical silicon is subjected to at least a thermal process to cause the metallurgical silicon to change in state from a first state to a second state, the second stage being a molten state not exceeding

05-19-2011

20130008372

METHOD FOR PURIFYING SILICON - A method for purifying silicon includes placing silicon to be purified and an aluminum-silicon alloy ingot, made from high purity aluminum in close contact in a closed environment to be subjected to heating under vacuum, such that the aluminum-silicon alloy ingot is melted into an aluminum-silicon melt. The temperatures are kept constant when the temperature M the interface of the silicon and the aluminum-silicon melt and the temperature at a free end of the aluminum-silicon melt reach 900° C. and 800° C. respectively. As the purified silicon begins to segregate and the interface, the heating apparatus is moved in step with the growth rate of the segregated silicon toward the silicon to be purified to maintain the temperatures at both ends of the aluminum-silicon melt. The segregated pure silicon is cut off upon the completion of dissolution of purified silicon and after cooling and air pressure recovery.

01-10-2013

20140109825

EQUIPMENT AND METHOD FOR PRODUCING CRYSTAL BY VERTICAL BOAT METHOD - Equipment for crystal growth by a vertical boat method includes a crucible enclosing a raw material, an ampoule encapsulating the crucible, and a crystal growth heater provided around the ampoule to heat the raw material. The raw material is melted into a raw material melt by the crystal growth heater, and a temperature of the raw material melt is controlled such that a crystal grows in the crucible from a bottom toward a top thereof. The crucible encloses GaAs as the raw material and Si as a dopant. The ampoule includes an additional B

04-24-2014

20120279440

METHODS FOR PURIFYING METALLURGICAL SILICON - A method for purifying silicon bearing materials for photovoltaic applications includes providing metallurgical silicon into a crucible apparatus. The metallurgical silicon is subjected to at least a thermal process to cause the metallurgical silicon to change in state from a first state to a second state, the second stage being a molten state not exceeding 1500 Degrees Celsius. At least a first portion of impurities is caused to be removed from the metallurgical silicon in the molten state. The molten metallurgical silicon is cooled from a lower region to an upper region to cause the lower region to solidify while a second portion of impurities segregate and accumulate in a liquid state region. The liquid state region is solidified to form a resulting silicon structure having a purified region and an impurity region. The purified region is characterized by a purity of greater than 99.9999%.

GaN Whiskers and Methods of Growing Them from Solution - Millimeter-scale GaN single crystals in filamentary form, also known as GaN whiskers, grown from solution and a process for preparing the same at moderate temperatures and near atmospheric pressures are provided. GaN whiskers can be grown from a GaN source in a reaction vessel subjected to a temperature gradient at nitrogen pressure. The GaN source can be formed in situ as part of an exchange reaction or can be preexisting GaN material. The GaN source is dissolved in a solvent and precipitates out of the solution as millimeter-scale single crystal filaments as a result of the applied temperature gradient.

07-25-2013

20130192517

Method And System For Alumina Nanofibers Synthesis From Molten Aluminum - A method for synthesizing monocrystalline alumina nanofibers by controlled liquid phase oxidation of a melt including molten aluminum. The method comprises two stages. During the first stage, metallic aluminum is melted and various additives are introduced into the melt. During the second stage, the alumina nanofibers are synthesized from the resulting melt in the presence of oxygen. In one or more embodiments, the inventive method is performed in a reactor. The reactor is designed to provide the heating and to enable melting of metallic aluminum. In addition, the reactor is designed to maintain a sustained temperature of between 660° C. and 1,000° C. When the additives are introduced into the molten aluminum, it is desirable to provide steady and uniform the stirring of the melt. To this end, the reactor may be provided with a stirring mechanism.

08-01-2013

20140230720

Direct band gap wurtzite semiconductor nanowires - Growth of GaP and III-V GaP alloys in the wurtzite crystal structure by vapor phase epitaxy (VPE) is provided. Such material has a direct band gap and is therefore much more useful for optoelectronic devices than conventional GaP and GaP alloys having the zincblende crystal structure and having an indirect band gap.

08-21-2014

Entries

Document

Title

Date

20100050932

Apparatus and Method of Direct Electric Melting a Feedstock - This invention relates to an apparatus and a method of direct electric melting a feedstock, such as high purity silicon for use in solar cells or solar modules. The continuous melting apparatus includes a first electrode opposite a second electrode and forming a melting zone. The electric current passes from the first electrode through a feedstock and enters the second electrode. The apparatus also includes an opening for draining a molten feedstock from the melting zones and a catch pan for receiving the molten feedstock from the opening.

03-04-2010

20100288187

METHOD FOR GROWING SILICON CARBIDE SINGLE CRYSTAL - In a method for growing a silicon carbide single crystal on a silicon carbide single crystal substrate by contacting the substrate with a solution containing C prepared by dissolving C into the melt that contains Cr and X, which consists of at least one element of Ce and Nd, such that a proportion of Cr in a whole composition of the melt is in a range of 30 to 70 at. %, and a proportion of X in the whole composition of the melt is in a range of 0.5 at. % to 20 at. % in the case where X is Ce, or in a range of 1 at. % to 25 at. % in the case where X is Nd, and the silicon carbide single crystal is grown from the solution.

11-18-2010

20100083896

METHOD FOR PRODUCING SIC SINGLE CRYSTAL - 5 to 30 at % of Ti and 1 to 20 at % of Sn or 1 to 30 at % of Ge are added to an Si melt, and SiC single crystal are grown from SiC seed crystal by holding the SiC seed crystal immediately beneath the surface of the Si melt in a graphite crucible while maintaining temperature gradient descending from the inner side of the Si melt to the surface of the melt.

04-08-2010

20100294195

METHOD FOR CHARGING WITH LIQUEFIED AMMONIA, METHOD FOR PRODUCING NITRIDE CRYSTAL, AND REACTOR FOR GROWTH OF NITRIDE CRYSTAL - A method for charging with liquefied ammonia comprising sequentially a feeding step of feeding gaseous ammonia in a condenser, a liquefaction step of converting the gaseous ammonia into a liquefied ammonia in the condenser, and a charging step of feeding the liquefied ammonia formed in the condenser to a vessel to thereby charge the vessel with the liquefied ammonia wherein a cooling step of feeding the liquefied ammonia formed in the condenser to the vessel and cooling the vessel by the latent heat of vaporization of the liquefied ammonia and a circulation step of feeding the gaseous ammonia formed through vaporization of the liquefied ammonia in the previous cooling step to the condenser are carried out between the liquefaction step and the charging step.

METHOD FOR GROWING SILICON CARBIDE SINGLE CRYSTAL - In a method for growing a silicon carbide single crystal on a silicon carbide single crystal substrate by contacting the substrate with a solution containing C by dissolving C into the melt that contains Si, Cr and X, which consists of at least one element of Sn, In and Ga, such that the proportion of Cr in the whole composition of the melt is in a range of 30 to 70 at. %, and the proportion of X is in a range of 1 to 25 at. %, and the silicon carbide crystal is grown from the solution.

11-18-2010

20100037815

Method For Producing A Single Crystal Of Semiconductor Material - A single crystal of semiconductor material is produced by a method of melting semiconductor material granules by means of a first induction heating coil on a dish with a run-off tube consisting of the semiconductor material, forming a melt of molten granules which extends from the run-off tube in the form of a melt neck and a melt waist to a phase boundary, delivering heat to the melt by means of a second induction heating coil which has an opening through which the melt neck passes, crystallizing the melt at the phase boundary, and delivering a cooling gas to the run-off tube and to the melt neck in order to control the axial position of an interface between the run-off tube and the melt neck.

02-18-2010

20130284084

CRUCIBLES - A method for manufacturing a crucible for the crystallization of silicium comprising the steps of •preparing a slurry of solids and liquids, said solids consisting of •silicon metal powder •up to 25% (w/w) SiC powder •up to 10% (w/w) SiN •up to 0.5% (w/w) of a catalyst •up to 1% (w/w) of a binder •forming the slurry into a green body of a crucible •heating the green body in a nitrogen atmosphere, optionally comprising inert gas, to react the silicon at least partially to silicon nitride.

10-31-2013

20120279439

METHOD AND APPARATUS FOR PURIFYING METALLURGICAL SILICON FOR SOLAR CELLS - A method improves yield of an upgraded metallurgical-grade (UMG) silicon purification process. In the UMG silicon purification process, in a reaction chamber, purification is performed on a silicon melt therein by one, all or a plurality of the following techniques in the same apparatus at the same time. The techniques includes a crucible ratio approach, the addition of water-soluble substances, the control of power, the control of vacuum pressure, the upward venting of exhaust, isolation by high-pressure gas jet, and carbon removal by sandblasting, thereby reducing oxygen, carbon and other impurities in the silicon melt, meeting a high-purity silicon standard of solar cells, increasing yield while maintaining low cost, and avoiding EMF reduction over time. An exhaust venting device for the purification process allows exhaust to be vented from the top of the reactor chamber, thereby avoiding backflow of exhaust into the silicon melt and erosion of the reactor.

11-08-2012

20100236472

METHOD FOR GROWING SILICON CARBIDE SINGLE CRYSTAL - A method for growing a silicon carbide single crystal on a single crystal substrate comprising the steps of heating silicon in a graphite crucible to form a melt, bringing a silicon carbide single crystal substrate into contact with the melt, and depositing and growing a silicon carbide single crystal from the melt, wherein the melt comprises 30 to 70 percent by atom, based on the total atoms of the melt, of chromium and 1 to 25 percent by atom, based on the total atoms of the melt, of X, where X is at least one selected from the group consisting of nickel and cobalt, and carbon. It is possible to improve morphology of a surface of the crystal growth layer obtained by a solution method.

METHOD OF PRODUCING SEMICONDUCTOR SINGLE CRYSTAL - Relates to a method of producing a semiconductor crystal having generation of a defect suppressed in the semiconductor single crystal. The production method includes the steps of: forming a boron oxide film on the inner wall of a growth container having a bottom section and a body section continuous to the bottom section; bringing the boron oxide film into contact with boron oxide melt containing silicon oxide to form a boron oxide film containing silicon oxide on the inner wall of the growth container; forming raw material melt above seed crystal placed in and on the bottom section of the growth container; and solidifying the raw material melt from the seed crystal side to grow a semiconductor single crystal.

01-10-2013

20130008371

METHOD FOR MANUFACTURING POLYCRYSTALLINE SILICON INGOT, AND POLYCRYSTALLINE SILICON INGOT - A method for manufacturing a polycrystalline silicon ingot includes unidirectionally solidifying a molten silicon upwardly from the bottom of a crucible, wherein the crucible is provided with silica deposited on the bottom of the crusible; and then dividing the degree of solidification in the crucible into a first zone from 0 mm to X in height (10 mm≦X<30 mm), a second zone from X to Y in height (30 min≦Y<100 mm) and a third zone of Y or more in height, based on the bottom of the crucible, wherein a solidification rate V1 in the first zone is set in the range of 10 mm/h≦V1≦20 mm/h and a solidification rate V2 in the second zone is set in the range of 1 mm/h≦V2≦5 mm/h.

01-10-2013

20110048316

High-Temperature Process Improvements Using Helium Under Regulated Pressure - A method for minimizing unwanted ancillary reactions in a vacuum furnace used to process a material, such as growing a crystal. The process is conducted in a furnace chamber environment in which helium is admitted to the furnace chamber at a flow rate to flush out impurities and at a predetermined pressure to achieve thermal stability in a heat zone, to minimize heat flow variations and to minimize temperature gradients in the heat zone. During cooldown helium pressure is used to reduce thermal gradients in order to increase cooldown rates.

03-03-2011

20090249997

METHOD OF PRODUCING GROUP III NITRIDE CRYSTAL, APPARATUS FOR PRODUCING GROUP III NITRIDE CRYSTAL, AND GROUP III NITRIDE CRYSTAL - In a method of producing a group III nitride crystal in which a melt holding vessel where a melt containing a group III metal and flux is held is accommodated in a reaction vessel and a group III nitride crystal is produced as a substance containing nitrogen is supplied from an outside to the reaction vessel through a pipe, the method includes a step of forming an accumulated part of a liquid in the pipe to thereby temporarily close the pipe before growing the group III nitride crystal in the melt holding vessel.

10-08-2009

20130112135

THERMAL LOAD LEVELING USING ANISOTROPIC MATERIALS - An apparatus for growing a silicon crystal substrate comprising a heat source, an anisotropic thermal load leveling component, a crucible, and a cold plate component is disclosed. The anisotropic thermal load leveling component possesses a high thermal conductivity and may be positioned atop the heat source to be operative to even-out temperature and heat flux variations emanating from the heat source. The crucible may be operative to contain molten silicon in which the top surface of the molten silicon may be defined as a growth interface. The crucible may be substantially surrounded by the anisotropic thermal load leveling component. The cold plate component may be positioned above the crucible to be operative with the anisotropic thermal load leveling component and heat source to maintain a uniform heat flux at the growth surface of the molten silicon.

05-09-2013

20100089310

DEVICE AND METHOD FOR PRODUCING SELF-SUSTAINED PLATES OF SILICON OR OTHER CRYSTALLINE MATERIALS - The device for producing a sheet of crystalline material by directional solidification of a material in liquid phase composed of a crucible provided with a bottom, side walls and at least one horizontal outlet slot arranged on a bottom part of a side wall. On its external surface in immediate proximity to the slot, the crucible presents electromagnetic means for creating magnetic repulsion forces on the material in liquid phase, at least at the level of the slot. An alternating current with a frequency comprised between 10 kHz and 300 kHz flows through the electromagnetic means. To foster stirring of the material in liquid phase, a low frequency can be used in addition to the above frequencies.

04-15-2010

20130036967

SELECTED METHODS FOR EFFICIENTLY MAKING THIN SEMICONDUCTOR BODIES FROM MOLTEN MATERIAL FOR SOLAR CELLS AND THE LIKE - A pressure differential is applied across a mold sheet and a semiconductor (e.g. silicon) wafer (e.g. for solar cell) is formed thereon. Relaxation of the pressure differential allows release of the wafer. The mold sheet may be cooler than the melt. Heat is extracted almost exclusively through the thickness of the forming wafer. The liquid and solid interface is substantially parallel to the mold sheet. The temperature of the solidifying body is substantially uniform across its width, resulting in low stresses and dislocation density and higher crystallographic quality. The mold sheet must allow flow of gas through it. The melt can be introduced to the sheet by: full area contact with the top of a melt; traversing a partial area contact of melt with the mold sheet, whether horizontal or vertical, or in between; and by dipping the mold into a melt. The grain size can be controlled by many means.

02-14-2013

20150292109

APPARATUS AND PROCESS FOR PRODUCING A SINGLE CRYSTAL OF SILICON - An apparatus for producing a single crystal of silicon comprises a plate with a top side, an outer edge, and an inner edge, a central opening adjoining the inner edge, and a tube extending from the central opening to beneath the bottom side of the plate;

METHOD OF PRODUCTION OF SiC SINGLE CRYSTAL - A method of production of SiC single crystal using the solution method able to stably maintain flatness of a growth surface, prevent polycrystallization, and grow a large sized SiC single crystal is provided. A method of growing a hexagonal SiC single crystal starting from a hexagonal SiC seed crystal held directly under a melt surface of an Si melt in a graphite crucible by maintaining in the Si melt a temperature gradient such that the temperature falls from the inside toward the melt surface of the Si melt, characterized by:

Method of Growing Single Crystals from Melt - The present invention relates to the technology of growing single crystals from melts on a seed crystal. The technical problem to be solved by the present invention is to provide a universal method of growing single crystals of various chemical composition, for example, of A2B6 and A2B5 type, and also single crystals of refractory oxides, such as sapphire. The technical result of the claimed invention is its universality with regard to the material of the single crystal to be grown, enhanced performance, and improved structural finish of resulting single crystals by ruling out melt overcooling in the coursed of growing. The technical result is attained by that in the method of growing single crystals from melt, which comprises fusing the starting material and pulling a single crystal by crystallization of the melt on a seed crystal with controlled removal of the crystallization heat and using independent heating sources constituting thermal zones, according to the invention, independent heating sources constitute two equal-sized coaxially arranged thermal zones, which make up a united thermal area for the melt and the single crystal being grown and are separated by the melt starting material being carried out heating the upper thermal zone with heater 30-50% of power required for obtaining the melt, until in the upper thermal zone maximum temperature is reached, which secure stable state of the solid phase of the seed crystal; then the remaining power is supplied to the lower thermal zone to the lower heater with maintaining constant temperature of the upper thermal zone till complete melting of the charge; the process of the single crystal enlargement and growing is conducted with controlled lowering of temperature in the upper thermal zone, the amount of power supplied to the lower thermal zone being preserved constant.

11-20-2008

20090158993

Method for producing a monocrystalline or polycrystalline semiconductore material - The invention relates to a method for producing a monocrystalline or polycrystalline semiconductor material by way of directional solidification, wherein lumpy semiconductor raw material is introduced into a melting crucible and melted therein and directionally solidified, in particular using the vertical gradient freeze method.

06-25-2009

20090090295

METHOD FOR GROWING SILICON INGOT - Provided is a method for growing a silicon ingot. According to an exemplary method, the method includes charging silicon in a quartz crucible, melting the silicon by heating the quartz crucible and applying a magnetic field of 500 Gauss or higher in the quartz crucible, and growing a single crystalline silicon ingot from the melted silicon while applying a magnetic field lower than 500 Gauss in the quartz crucible. As a result, by appropriately controlling the internal pressure of the quartz crucible or the application time and the magnitude of the magnetic field, it is possible to easily accelerate crystallization of the internal surface of the quartz crucible to thereby prevent flaking of the crystals. Consequently, it is possible to grow the silicon ingot of good properties.